This is actually a collection of routines. They all work in generally the same way, but beacuse they handle different types of images, I find it easier to maintain custom scripts for each type of image. The common feature is that we use a ds9 gui to specify the X,Y position of a star in the image for which we know Ra,Dec. Supplying a pixel scale and an orientation angle we can then build and install an approximate, possibly rough, WCS in the FITS header.
We have a good idea of the pixel scale for an HET acquisition camer image and a pretty good calibration that gives us the Y-axis position angle (i.e. direction to North) given the HET structure azimuth. Using rough_wcs_acam, we simply mark a star of known sky position. We are queried for the sexigecimal Ra,Dec and the HET structure azimuth and a local image with a rough WCS FITS header is produced. We can use a full image path for the image name.
My image is: /home/sco/ACAM/gstar_sets/20160124/Point1/Set1/20160124T064413.3_acm_sci.fits I know a bright star was placed near the IHMP: G191B2B 05:05:30.50 +52:49:57.0 2000 320.266 Name RA DEC EQU AZ % ls % pwd /home/sco/work To run the code: rough_wcs_acam /home/sco/ACAM/gstar_sets/20160124/Point1/Set1/20160124T064413.3_acm_sci.fits During part of the run I would see: X,Y = 176.10 383.61 Mag30 = 14.739 Peak = 20271.00 Enter OBJECT,RA,DEC,AZ (HD86778 12:12:12.12 +20:20:20.0 120.0): G191B2B 05:05:30.50 +52:4990l:57.0 320.266 % ls 20160124T064413.3_acm_sci.fits 20160124T064413.3_acm_sci.info S/In the last line above I show how I have manually entered the target name, the Ra,Dec, and structure azimuth. Note also that the target image has an X,Y centroid, magnitude (Mag30 = 30 - 2.5log(Flux_above_sky)) and Peak value (above flux) reported after it is measured on the image. after the run we see the local image created (and an info file).